


Tempted by the Fruit of Another

by alien_lord



Category: Harry Potter - J. K. Rowling
Genre: Bathroom Sex, Dirty Talk, F/M, Forbidden Love, Heterosexual Sex, Incest, Sex, TW for Incest, boredom sex, cousin sex, implied cousin sex, implied threesome, quickie sex, tw incest, unprotected sex
Language: English
Status: Completed
Published: 2017-08-30
Updated: 2017-08-30
Packaged: 2018-12-21 18:53:16
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,606
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/11950503
Author URL: https://archiveofourown.org/users/alien_lord/pseuds/alien_lord
Summary: Sirius wants Narcissa, and he knows it's forbidden. Narcissa sees him looking, and plays with him. She follows him out of class and she propositions him. He doesn't decline.(Please read tag warnings. I don't want anyone upset by this fic.)





	Tempted by the Fruit of Another

Sirius hadn’t been raised with his cousins, in fact, he didn’t know them personally until they all went to school at Hogwarts together. Sirius and Regulus had been separated for most of their lives, their mother refusing to let them see any other children, and when they went to Hogwarts it had been a culture shock. Sirius had adapted well, his anxieties morphing into loud charisma, hiding his fears inside. Regulus, was more introverted, and didn’t bond with people the way Sirius did. 

In regards to romantic interests, Regulus had none. He wasn’t interested in dating, or sex. He was completely content with his loneliness, it didn’t matter to him. Sirius on the other hand, craved human interaction, and the love that he’d never received. 

The object of his affection was Narcissa, and while he knew that was forbidden, it didn’t stop him from wanting her any less.   
There was something about her dignified walk, her long, thin legs, and the sheet of platinum blonde hair that flowed when she walked that drove Sirius crazy. His heart palpitated when he saw her, and it was like his world stopped. She was tied to Lucius Malfoy, and everyone knew that the two would marry when they were finished Hogwarts. 

He hated Malfoy more than the others in his group. Malfoy hung out with several other Slytherin’s that looked like they would murder your mother in front of you, and then eat at your kitchen table. Malfoy was also dignified, a sneer plastered on his pale face at all times. His long hair was pulled back in a low ponytail, a black ribbon holding it back. 

Sirius watched Narcissa wherever she went, and he knew that she saw him. Most times she’d pretend she didn’t see, flicking her long hair over her shoulder, barely glancing in his direction. Other times, when she was bored, she’d want to play along. Once, in class, she’d seen him staring, and with a quick little smile, slowly tugged up her robe, flashing way too much leg than was appropriate. 

It was the little things she did that drove him crazy. During potions, she walked past him, ‘accidentally’ spilling some water on his crotch, and bent over in his face, apologizing profusely as she dabbed at the water, her pale hands with perfectly shaped nails sliding over his inner thigh. Sirius’s face was so red he worried about it setting on fire. 

This particular day, he’d been watching her during transfiguration. He got up half way through the class to go to the bathroom, in reality he was going to sit in the bathroom and probably jerk off because he was feeling particularly sexually repressed that day. After being in the bathroom for a couple minutes, he heard footsteps. Curious, as typically this bathroom was abandoned, he peaked out of the stall, and his heart jumped in his chest. 

Narcissa had walked into the bathroom, her straight hair hanging perfectly behind her. She glanced around the bathroom, and walked quietly . He opened the door to the stall, and stepped outside. 

“Little lost?” He asked her with a laugh, trying to play it cool, trying to disguise the palpitations he was feeling in his chest.

She smirked a little bit, her pretty face pulling up at the mouth. “Not in the least, Black.” Glancing behind her, she added, “I left class to find you-“  
Sirius felt like his chest was constricting. This had to be some sort of joke, something set up by Lucius, or the others. 

“Did Malfoy send you here?” He asked, snapping a little as he looked her over. He wanted her so bad, but he wasn’t going to let himself fall into some kind of trap, especially set by Malfoy. 

She shook her head, pursing her lips. He had other ideas for what he wanted those lips to be doing.   
“I wanted to see you-“ she took a step closer, and he took a step backwards. 

Narcissa’s smile grew a little, and she didn’t stop her approach. She stopped just in front of him, touching one long nail to his chin, gently. “Bella’s in love with you-“ pausing a second, she licked her lower lip, before continuing. “I didn’t want to have you, it would upset her, but-“ she breathed, her voice thick with lust. “Something about being able to have you anyway, it just- turns me on.”

Sirius’s heart pounded in his chest. The idea that her sister, Bellatrix, also his cousin, wanted him, while a turn on, was also terrifying. Bellatrix was a terrifying young woman, and Sirius just wasn’t interested in her sexually. “You’re lying-“ he countered, not sure what else to say.   
Narcissa breathed on the crook of his neck, running a hand down his chest. “Am I?” Her nails dug into the front of his robes, and they made eye contact. Her icy blue eyes stared into his dark eyes, and they held the gaze for too long. Reaching up, she grabbed the back of his hair, nails twisting into the back of his curly hair. "Lucius is so boring in bed, I need something else-" she whispered, "Something dangerous."

“I want you to fuck me –“ her lips were wet and pink, her voice cracking with desire, “Right now-“  
Sirius didn’t need to be asked again, his mouth crashed against his, and she shoved him back into the bathroom stall, slamming the door behind them. Their robes were ripped off, and fell to the floor, Sirius admired her naked body. She was slim, with perfect, perky breasts. Her bush was trimmed, platinum blonde just like her long hair. 

She ran her nails down his chest, leaving scratch marks that he knew would take a while to fade. Kneeling down, she kissed a trail down his stomach, over his treasure trail, and down to his erect dick. Licking a trail down the underside, Sirius let out a controlled moan, and she took him in her mouth. He bucked his hips into her mouth, enjoying the feeling. 

After a few minutes, she got bored of sucking him off, and wanted him inside of her. “Fuck me-“ she sighed, voice breathy and thick.   
He yanked her up, turning her around so that her hands were pressed against the stall door. He fingered her from behind, spreading her open with his fingers, and rubbing at her clit. She rubbed herself back on her fingers. “Do you like that?” He asked, his voice low and desperate.   
She nodded her head, long hair falling around her face as he leaned over to lick her pussy from behind. Her legs shook as he sucked and licked her clit, tongue sliding around her soft skin, tasting her on his tongue. 

Narcissa moaned, her orgasm close. He felt her legs shaking around him, and he didn’t stop what he was doing. A couple minutes later with a high pitched shriek, she came, and he tasted her juices on his tongue.  
“I want you to fuck me as hard as you can-“ she gasped, and thrust her hips back toward him. 

Grabbing her by the back of the hair, he finally entered her, yanking her head back as he thrust into her. Her vagina was still contracting from her orgasm, and he gasped as she squeezed him. He started to thrust, and picked up a rhythm, fucking her hard from behind. 

“Fuck me, oh god-“ she gasped, her voice cracking as she thrust herself back on him with vigor. “I want you to fuck me and Bella-“ her voice sounded so desperate, and Sirius was so turned on, he agreed. “I’ll fuck you both-“ he moaned, not even thinking about what he’d agreed to.   
“Oh god, don’t stop-“ she moaned, and he bit the bottom of his lip hard, trying not to cum. 

It wasn’t too long after that though, that he knew he needed to finish. His hands gripped her waist as he pulled her back as hard as he could on his dick. “I’m going to cum-“ he gasped, throat raw. 

“Cum on my back-“ she started to say, but it was too late, with a moan, he came inside her, shuddering and leaning forward. With a gasp, he enjoyed the last few seconds of his orgasm, before slowly pulling his dick out of her leaking pussy.   
“You were supposed to cum outside of me-“ she turned around, catching her breath and stretching out her back, a frown on her face. 

“What do you care?” He asked her, trying to catch his own breath. “If you have a baby, it’ll still be pure blood, you can just tell Lucius it is his-“.   
Grabbing his robe off the floor, he pulled it back on, and she did the same. 

Stepping out of the stall, she smoothed her hair down, and in seconds she was back to her beautiful self, you could barely tell she’d been fucked raw minutes before. 

“Don’t leave the bathroom until I’ve been gone for a few minutes-“ she told him, bitch expression back on her face. “I don’t want anyone seeing us together-“ she raised her face, chin jutting at him. 

Sirius smirked, “Wouldn’t want Lucius finding out you fucked your cousin-“ He ran a hand through his tousled hair, feeling a little cocky after sex.   
She cut him off with a wave of her hand. “Enough-“ and he stopped, cut off. 

As she turned to leave, flipping her hair over her shoulder one last time, she added, “I enjoyed having you, Black. Let’s do it again, sometime-“ and she disappeared out of the bathroom, leaving Sirius awash in lust.

**Author's Note:**

> I kind of want to write a second part of this, a follow up to the implied Bellatrix/Narcissa/Sirius, and or the possible pregnancy for Narcissa having unprotected sex. Tell me what you think! <3 Thanks for reading!


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